Does blender have the concept of instances and params?
This can be accomplished with Node Groups.

Grouping nodes can simplify a node tree by allowing instancing and hiding parts of the tree. Both material and composite nodes can be grouped.
Also nested node groups are supported. I.e. a node group can be inserted or created inside another node group.

For example, creating a 'GlossyMaterial' shader group with an input for color. Node Groups can be linked/appended across files and shared between many material instances.
Further resources:

Introduction to Node Groups